Elon Musk said China wants assurances that the rare-earth magnets needed to build Optimus will not be used for "military purposes."

Tesla is facing supply chain and geopolitical roadblocks in ramping up production of its humanoid robot, Optimus. During the Q1 earnings call, CEO Elon Musk said mass production is months away, citing rare earth export restrictions from China as a major hurdle.

During an earnings call following Tesla's lackluster calendar Q1 results in which revenue slumped 20 percent to $12.925 billion and net income plunged 70 percent year-on-year to $420 million, Musk talked of difficulties in obtaining rare earth magnets used in robot motors.